Implement inline %_IsJSProxy() for full codegen and Hydrogen

src/x64/full-codegen-x64.cc

Index: src/x64/full-codegen-x64.cc
diff --git a/src/x64/full-codegen-x64.cc b/src/x64/full-codegen-x64.cc
index d4ed767ecad286cf2a0548f3e7b766cf6f5dbc8e..4817e502ebb7cd1edb06391b5e119f9ffe321c8c 100644
--- a/src/x64/full-codegen-x64.cc
+++ b/src/x64/full-codegen-x64.cc
@@ -3330,6 +3330,31 @@ void FullCodeGenerator::EmitIsRegExp(CallRuntime* expr) {
 }
 
 
+void FullCodeGenerator::EmitIsJSProxy(CallRuntime* expr) {
+  ZoneList<Expression*>* args = expr->arguments();
+  DCHECK(args->length() == 1);
+
+  VisitForAccumulatorValue(args->at(0));
+
+  Label materialize_true, materialize_false;
+  Label* if_true = NULL;
+  Label* if_false = NULL;
+  Label* fall_through = NULL;
+  context()->PrepareTest(&materialize_true, &materialize_false, &if_true,
+                         &if_false, &fall_through);
+
+  __ JumpIfSmi(rax, if_false);
+  Register map = rbx;
+  __ movp(map, FieldOperand(rax, HeapObject::kMapOffset));
+  __ CmpInstanceType(map, FIRST_JS_PROXY_TYPE);
+  __ j(less, if_false);
+  __ CmpInstanceType(map, LAST_JS_PROXY_TYPE);
+  PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
+  Split(less_equal, if_true, if_false, fall_through);
+
+  context()->Plug(if_true, if_false);
+}
+
 
 void FullCodeGenerator::EmitIsConstructCall(CallRuntime* expr) {
   DCHECK(expr->arguments()->length() == 0);